# Luxembourg IBAN Validator (LU, length 20)

> Luxembourg IBAN Validator (LU, length 20) is a paid API for AI agents from agentshelf.syntexa.ch, paid per call via x402, $0.006/call, status unknown (last checked 2026-09-29).

Validates whether a given string is a structurally correct, mod-97-valid Luxembourg (LU) IBAN of exactly 20 characters.

## Facts

- Endpoint: POST https://agentshelf.syntexa.ch/v1/check-iban-lu?utm_source=zero.xyz
- Price: $0.006/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/luxembourg-iban-validator-lu-length-20-e74d5f92
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_bmoz6uh98MBLSJwL7ecbu

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability luxembourg-iban-validator-lu-length-20-e74d5f92 -d '<json body>'
```

Example prompt: Can you check whether LU28 0019 4006 4475 0000 is a valid Luxembourg IBAN — make sure it passes the mod-97 checksum and is the right 20-character format?

## When to prefer this

Use this endpoint when you specifically need to validate a Luxembourg (LU) IBAN of exactly 20 characters using the mod-97 algorithm. Prefer the free sandbox endpoint POST /v1/sandbox/check-iban-lu first for testing. For other country IBANs, use the corresponding sibling endpoints (e.g. NL for Netherlands, SE for Sweden, PT for Portugal). This endpoint is appropriate when operating in a paid production environment and a Luxembourg IBAN must be definitively validated.

## Known failure modes

- IBAN too short or too long (must be exactly 20 characters) — returns invalid
- Non-LU country code prefix — may return invalid or error
- Mod-97 checksum fails — returns invalid
- Malformed or empty input — may return 400 or validation error
- Payment failure (insufficient USDC) — 402 response blocking the call

## How this service works

Call when an agent needs whether an IBAN is a mod-97-valid LU number of length 20. Exact $0.006 USDC. Prefer unpaid POST /v1/sandbox/check-iban-lu first.

## Output

Returns a boolean or structured result indicating whether the submitted string is a valid Luxembourg (LU) IBAN: 20 characters long and passing the mod-97 checksum algorithm. May include the validated IBAN, a validity flag, and possibly an error reason if invalid.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "data": {
   "description": "JSON value for schema-check SKUs. Omit it on string checks such as email or IBAN."
  },
  "value": {
   "type": "string",
   "examples": [
    "LU12AAAA000000000000"
   ],
   "maxLength": 20000,
   "minLength": 1,
   "description": "Value to check. The route description names the format: email, phone, IBAN, postal code, VAT, national id, or similar."
  },
  "schema": {
   "description": "JSON Schema document for schema-check SKUs. Omit it on string checks."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/luxembourg-iban-validator-lu-length-20-e74d5f92/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentshelf.syntexa.ch](https://www.zero.xyz/host/agentshelf.syntexa.ch/llms.txt)